1. Field of the Invention
This invention relates to a control apparatus for a turbine-type flow meter and, more particularly, to a control apparatus for correcting measured values of a rate of flow through a turbine-type flow meter.
2. Prior Art
Known turbine-type flow meters for metering the rate of a flow of fluid to be measured utilize an arrangement which involves detecting the rotational speed of a turbine rotating in response to the velocity of the fluid flow such as to produce pulses and integrating the pulses either to indicate the integrated value or output a signal representing a unit amount of the fluid when the integration reaches or exceeds a predetermined value.
In a pipe-line for supplying a fluid to be measured, such as municipal gas or the like, to a house or other premises, a flow meter is provided for every house which is adapted to measure the flow rate of the fluid over a wide range between extremely low and high quantities. (Since the fluid to be measured is generally municipal gas, it will hereinafter be referred to as a "gas".) An example of such a conventional flow meter is described in Japanese Utility Model Laid-Open Application No. 15520/1986.
In such conventional turbine-type flow meters, problems are encountered in that when the flow rate of the gas abruptly drops, the inertia of the turbine rotor means that a relatively long time is required for the rotational speed of the turbine rotor to decelerate to a speed which corresponds to the lower flow rate and during this period of time the measured value of the flow rate may exceed the actual figure.